# Define here the models for your spider middleware
#
# See documentation in:
# https://docs.scrapy.org/en/latest/topics/spider-middleware.html

from scrapy.http import HtmlResponse
import time
from scrapy import signals
from selenium.webdriver import Chrome  # 引入selenium浏览器自动框架、选择谷歌浏览器chrome类
from selenium.webdriver.chrome.service import Service  # 防止被反扒，
from selenium.webdriver.chrome.options import Options  # 隐藏浏览器痕迹的参数
from selenium.webdriver.common.by import By  # 定位标签by
from selenium.webdriver.common.action_chains import ActionChains  # 动作链条，拖动，下拉什么的
# useful for handling different item types with a single interface
from itemadapter import is_item, ItemAdapter


class RzySpiderMiddleware:
    # Not all methods need to be defined. If a method is not defined,
    # scrapy acts as if the spider middleware does not modify the
    # passed objects.

    @classmethod
    def from_crawler(cls, crawler):
        # This method is used by Scrapy to create your spiders.
        s = cls()
        crawler.signals.connect(s.spider_opened, signal=signals.spider_opened)
        return s

    def process_spider_input(self, response, spider):
        # Called for each response that goes through the spider
        # middleware and into the spider.

        # Should return None or raise an exception.
        return None

    def process_spider_output(self, response, result, spider):
        # Called with the results returned from the Spider, after
        # it has processed the response.

        # Must return an iterable of Request, or item objects.
        for i in result:
            yield i

    def process_spider_exception(self, response, exception, spider):
        # Called when a spider or process_spider_input() method
        # (from other spider middleware) raises an exception.

        # Should return either None or an iterable of Request or item objects.
        pass

    def process_start_requests(self, start_requests, spider):
        # Called with the start requests of the spider, and works
        # similarly to the process_spider_output() method, except
        # that it doesn’t have a response associated.

        # Must return only requests (not items).
        for r in start_requests:
            yield r

    def spider_opened(self, spider):
        spider.logger.info("Spider opened: %s" % spider.name)


class RzyDownloaderMiddleware:
    # Not all methods need to be defined. If a method is not defined,
    # scrapy acts as if the downloader middleware does not modify the
    # passed objects.

    @classmethod
    def from_crawler(cls, crawler):
        # This method is used by Scrapy to create your spiders.
        s = cls()
        crawler.signals.connect(s.spider_opened, signal=signals.spider_opened)
        return s

    def process_request(self, request, spider):
        # Called for each request that goes through the downloader
        # middleware.
        opt = Options()
        opt.add_argument('--disable-blink-features=AutomationControlled')
        # 类似于headers操作.  隐藏浏览器请求头文件
        # opt.add_experimental_option('detach', True)  # 防止报错，浏览器自动关闭
        driver = Chrome(options=opt)  # 实例化chrome.   添加参数
        driver.maximize_window()  # z最大化窗口
        driver.get(request.url)  # 自动化，打开网页
        time.sleep(3)  # 等待3秒，让浏览器加载数据，渲染数据...
        # driver.execute_script(js)
        time.sleep(1)
        time.sleep(1)
        html = driver.page_source
        return HtmlResponse(url=request.url, body=html.encode('utf-8'), encoding='utf-8')

    def process_response(self, request, response, spider):
        return response

    def process_exception(self, request, exception, spider):
        # Called when a download handler or a process_request()
        # (from other downloader middleware) raises an exception.

        # Must either:
        # - return None: continue processing this exception
        # - return a Response object: stops process_exception() chain
        # - return a Request object: stops process_exception() chain
        pass

    def spider_opened(self, spider):
        spider.logger.info("Spider opened: %s" % spider.name)
